Rex-C100 PID - CKC Tinner - Troubleshooting

[JK29]

What's up Beer guys! I'm a custom knifemaker... and I'm finding out that you guys have a community that is well versed in operating PID controllers! I'm acurrently using this RexC100 to operate my tempering oven. I'm hoping you guys could help me out with the settings to get it operating in a tighter window! I'm hoping someone is versed in the Rex-C100 CKC Tinner PID! I'm having some issues.... #cheapEbayPID

Here is a video of what it's doing:

00:00 - 00:26 ; PID is holding a temp above the set-point (But I don't think it's the actual temp of the oven... notice the discrepancy from the red number to the thermometer values)

00:26 - 1:29 ;PID drops below 399 and loses it's mind! ... I think the red number then comes back down to the actual temperature.




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To elaborate on the issue... I charted this out with a stopwatch! PID was set and auto-tuned to 400F.


Exact testing set-up (Auto-Tuned to 400 with this set-up twice in a row) (Right cooking probe is what is charted in Orange Below):



It oscillates on about a 12 min cycle:



Notes/Misc:

• Check out the sharp drops and gains on the PID temp.
• I wonder if there is a frequency or dead-band setting that I could change? The oven stays shut off for a long time after it hits the 420 mark.
• I feel like a ~57 degree fluctuation is unacceptable! LOL
• My Rex-C100 is the knock-off version that only utilizes 3 digit codes instead of 4 digit codes for most of the options.
• I can't get the df setting below 001

Thanks for any help!
JK29

 

[JK29]

00:00 - 00:26 ; PID is holding a temp above the set-point (But I don't think it's the actual temp of the oven... notice the discrepancy from the red number to the thermometer values)

00:26 - 1:29 ;PID drops below 399 and loses it's mind! ... I think the red number then comes back down to the actual temperature.

 

[JK29]

Could a moderator move this to "Electric Brewing" ? I posted in the wrong forum.

Thanks,
JK29